Level measuring instrument with radar system on chip

ABSTRACT

A level measuring instrument is provided, including a microwave integrated circuit in a form of a radar system on chip with several transmission channels, each configured to generate a high-frequency transmission signal, and one or more receiving channels, each configured to receive reflected signals from a product surface; a noise level reduction device configured to increase a signal-to-noise ratio of a received signal, which relates to the reflected signals from the product surface, by averaging results of several measurements carried out in succession in time; and/or a signal level increasing device configured to combine two of the several transmission channels to produce a combined transmission signal with increased power and/or to combine two of the receiving channels to produce a combined reception signal with increased power. A method for measuring a level of a medium in a container or a surface topology of the medium is also provided.

TECHNICAL FIELD

The invention relates to level measurement. In particular, the inventionrelates to a level measuring device comprising a microwave integratedcircuit in form of a radar system on chip, a method for measuring alevel of a medium in a container, a method for measuring a topology of asurface of a medium in a container, a program element and acomputer-readable medium.

BACKGROUND

Level measurement with radar is state of the art today. In contrast tomany other areas, the breakthrough for radar technology in levelmeasurement was only possible after extremely small reflection signalscould be detected and processed by the electronics of the measuringinstruments.

Modern measuring instruments are not only characterized by a hightransmission frequency, which can typically be in the range of 75 to 85GHz, but are also capable of reliably processing amplitude differencesof the reflected signal in a range of up to 120 dB.

This has been made possible by the use of very low-noise high-frequencycircuit components, usually in the form of monolithic microwaveintegrated circuits (MMICs) based on gallium arsenide (GaAs). The use ofGaAs components has also made it possible to increase the high frequencypower available for measurement. However, a disadvantage of thissolution is the increased price of the components.

SUMMARY

It is an object of the invention to provide a level measuring instrumentwith a microwave integrated circuit in the form of a radar system onchip suitable for level measurement.

This object is solved by the subject matter of the independent patentclaims. Further developments of the invention are stated in thesub-claims and the following description.

A first aspect of the invention relates to a level measuring instrumentwith a microwave integrated circuit in the form of a radar system onchip. Such a radar system on chip is a highly integrated MMIC withcircuit components for digital functions which, according to anembodiment, is capable of integrating the complete functionality of aradar system for signal generation, signal processing and the conversionof the received signals into a digital representation on a single radarchip.

The Radar System on Chip (RSOC) comprises several transmission channels,each of these transmission channels designed to generate ahigh-frequency transmit signal with a frequency in the gigahertz range,for example in the range of 75 to 85 GHz or above. One or more receivingchannels can also be provided, whereby these are set up to receive ineach case a transmission signal reflected on the product surface.

A noise level reduction device may be provided which is designed toincrease, i.e., improve, the signal-to-noise ratio of the receivedsignal. In this case, the received signal is the signal received by thelevel measuring instrument which is due to the emitted signals reflectedon the product surface. The signal-to-noise ratio is increased byaveraging the results of several successive measurements.

Alternatively or additionally a signal level increasing device isprovided, which is arranged for combining at least two of thetransmission channels to generate a combined transmission signal withincreased power and/or for combining at least two of the receivingchannels to generate a combined reception signal with increasedreception power.

This signal level increase results in that the emitted signal has ahigher overall emitted power for the same power of the level measuringinstrument or the radar system on chip, so that even weaker reflectingmedia or objects can be reliably detected. This ultimately leads to asignal improvement.

The noise level reduction device behaves accordingly. With the sameoverall performance of the radar system on chip, the overall measurementresult is improved because the signal-to-noise ratio is increased. Thisalso leads to an improvement of the signal, which makes it possible touse certain radar systems on chip for level measurement, as otherwisethe measuring results would not be sufficiently accurate.

According to an embodiment of the invention, the noise level reductiondevice is configured, after averaging the results of severalmeasurements carried out in succession in time, to determine whether asufficient number of measurements have been averaged to achieve a givenmeasurement quality. If this measurement quality has not been achieved,further measurements are triggered, the results of which are also fed tothe averaging device in order to further improve the measurement resultby increasing the signal-to-noise ratio.

The decision as to whether a sufficient number of measurements have beenaveraged can be made, for example, by considering the threshold values.If the signal-to-noise ratio obtained by averaging is below apredetermined threshold value, further echo curves and/or measurementresults are generated and included in the averaging process. Thisprocess can be repeated several times until the signal-to-noise ratiohas the desired quality.

According to a further embodiment of the invention, the level measuringdevice is configured as a frequency-modulated continuous wave (FMCW)signal level measuring device, wherein each of the measurements carriedout in succession in time comprises a frequency sweep, for example at astarting frequency of 75 GHz up to a maximum frequency of 85 GHz.

According to a further embodiment of the invention, the microwaveintegrated circuit comprises at least one integrated analog-to-digital(A/D) converter, arranged to generate the received signal in the form ofa digitized intermediate frequency signal which is due to one or moretransmitted signals reflected at the product surface.

According to another embodiment, the digitized intermediate frequencysignals generated by the A/D converter are averaged by the noise levelreduction device.

According to another embodiment of the invention, an antenna isconnected to at least two (or even all) of the transmission channels.Likewise, an antenna is connected to at least two (or even all) of thereceiving channels. In particular, it may be provided that certain (orall) transmitting channels are also used simultaneously as receivingchannels.

According to another embodiment of the invention, the microwaveintegrated circuit is based on BiCMOS technology in which SiGe and CMOScircuit elements are combined.

According to another embodiment of the invention, the microwaveintegrated circuit is based on SiGe technology.

According to another embodiment of the invention, the microwaveintegrated circuit is based on HF-CMOS technology and has high-frequencycircuit parts for frequencies of 75 GHz or more.

According to a further embodiment, as already mentioned, each emittingchannel is also a receiving channel, equipped to receive the emittedsignal reflected on the product surface.

According to a further embodiment of the invention, the level measuringinstrument is configured to detect the topology of a medium in acontainer, i.e., it is capable of scanning the surface of the medium bydigital beam forming.

Another aspect of the invention relates to a method of measuring a levelof a medium in a container or a topology of a surface of the medium. Ahigh-frequency transmission signal with a frequency of, for example, 75GHz or more is generated. This is performed with one of severaltransmission channels. The emitted signals reflected on the productsurface are then received by several receiving channels. The radarsystems on chip described above and below can be used for this purpose.

To increase the signal-to-noise ratio of a received signal, which is dueto the emitted signals reflected at the product surface, the results ofseveral measurements carried out one after the other in time areaveraged. As an alternative or in addition, two or more of the emittingchannels are combined to generate a combined emitted signal withincreased power. Alternatively or additionally, two or more of thereceive channels are combined to produce a combined receive signal withincreased power.

A further aspect of the invention relates to a program element which,when executed on a processor of a level gauge, instructs the level gaugeto perform the steps described above and below.

Another aspect of the invention relates to a computer-readable medium onwhich the program element described above is stored.

The properties described below with regard to the level measuringinstrument can also be implemented as process steps. Conversely, all theprocess steps described in the following can be implemented in the levelmeasuring instrument.

In the following, embodiments of the invention are described withreference to the figures. If the same reference signs are used in thefollowing figure description, they denote identical or similar elements.The drawings in the figures are schematic and not to scale.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a level measuring instrument installed in a tank.

FIG. 2 shows another level measuring instrument.

FIG. 3 shows another level measuring instrument.

FIG. 4A shows a frequency sweep of a transmitted signal from a levelradar.

FIG. 4B shows a sequence of several frequency sweeps of a transmittedsignal from a level radar.

FIG. 5 shows several successive frequency sweeps of a transmissionsignal of a level radar unit.

FIG. 6 shows an example of averaging.

FIG. 7 shows a flow chart of a process according to an embodiment of theinvention.

FIG. 8 shows a level measuring instrument according to an embodiment ofthe invention.

FIG. 9 shows a level measuring instrument according to a furtherembodiment of the invention.

FIG. 10 shows a level measuring instrument according to a furtherembodiment of the invention.

FIG. 11 shows a level measuring instrument according to a furtherembodiment of the invention.

FIG. 12 shows a level measuring instrument with a container according toanother embodiment of the invention.

FIG. 13 shows a flow chart of a process according to an embodiment ofthe invention.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows a level measuring instrument in the form of a level radar.The measuring device 101 generates a transmission signal 103 by means ofa control circuit 112 and a high frequency circuit 102 and radiates thissignal in the direction of a product surface 105 by means of an antenna104. The product 106 reflects only a small part 107 of the energy of theemitted signal back to the level gauge. In the high frequency circuit102, the reflected signal is converted into a low frequency intermediatefrequency signal and fed to an analogue-digital converter circuit 108.This digitizes the low-frequency echo signal and passes the digitalvalues on to a signal processing circuit, for example a processor 109.Within this processor, the distance to the medium is determinedaccording to certain procedures. The measured value determined in thisway is made available to the outside world either wirelessly or by wire.Normally a so-called two-wire interface 111 is used at this point, whichon the one hand supplies the sensor 101 with power and on the other handserves to signal the measured value to the outside by setting a currentvalue proportional to the measured value in the range between 4 . . . 20mA within wire 111.

The transmission frequency commonly used in level radar equipment asshown in FIG. 1 is in the range of 6 GHz, 24 GHz or between 75 GHz and85 GHz. Especially for the last mentioned frequency range, up to nowunhoused GaAs semiconductor components are used, which are expensive dueto the semiconductor technology itself, and which also have to beprocessed in series in a cost-intensive way by bonding on the circuitboard.

In recent years, increased efforts have been made to realize MMIC'sbased on less expensive semiconductor materials. For example, MMICsbased on silicon germanium (SiGe), which in comparison to galliumarsenide devices not only reduces costs but also enables the transitionto higher frequencies. However, if highly integrated MMICs based on SiGeare used, which integrate most of the circuitry necessary for analogsignal generation and signal processing on one chip, the noise increases(the signal-to-noise ratio becomes lower) and the maximum transmissionpower that can be provided by such circuitry decreases.

Whereas in earlier times it was proposed to integrate analog circuitcomponents on a chip, embodiments of the present invention aim at usinga level measuring instrument with a radar system on chip (RSOC). Theintegration of CMOS circuit components for digital functions makes itpossible to integrate the complete functionality of a radar system forsignal generation, signal processing and the transfer of the receivedsignals into a digital representation on a single radar chip. For thispurpose, SiGe and CMOS circuit elements (BiCMOS) can be combined. It hasalso proved possible to realize high-frequency circuit parts inspecialized CMOS technology (HF-CMOS), so that the integration ofdigital circuit parts on the same chip up to complete processors istechnically feasible, so that single-chip radar systems can be builtwhich can be used for level measurement.

The requirements for radar systems for level measurement differconsiderably from those of other applications where the accuracy of themeasurement and energy efficiency are not so much important, but ratherthe minimization of the measurement time. An important feature ofindustrial level measuring instruments is that even extremely weakreflections of a bulk solid must be detected metrologically. By usingGaAs MMICs with inherently low inherent noise and high emitted power,even the smallest reflection signals can be reliably processed. Asignificant reduction in the costs of a level radar instrument, on theother hand, can only be achieved by using low-cost semiconductortechnologies (SiGe, HF-CMOS) and further integration. At first glance,the reduced emitted level and increased inherent noise of thelast-mentioned technologies thus stand in the way of their use in thearea of level measurement.

In the following a solution is proposed how low-cost BiCMOS and HF-CMOSbased integrated radar chips can be used in industrial radar levelmeasurement devices.

FIG. 2 shows a first step to reduce the cost of a level meter 100, 205.By using components 201 based on BiCMOS or HF-CMOS, a first integrationstep can be taken. The control circuit 112, which, depending on thedesired modulation of the transmitted signal 103, can be implemented,for example, in the form of a PLL, fractional PLL, or fractionalrational PLL, and can be integrated as a digital circuit component withthe integrated high-frequency circuit parts on a common IC 201.

Externally, this IC only has a high-frequency interface 204 forconnecting one or more antennas 104, an analog interface 202 for readingthe low-frequency intermediate frequency signals and a digital interface203 for controlling and parameterizing the chip. Due to the omission ofGaAs as a semiconductor material, the properties of such a systemdeteriorate in comparison with the structure of FIG. 1, both with regardto the inherent noise of the semiconductor circuitry and with regard tothe maximum transmission level that can be generated, both of whichresult in a reduced range of the amplitude differences of the reflectedecho signal that can be detected by the system.

FIG. 3 shows a further integration step. In addition to thehigh-frequency circuits 102 and the control circuit 112, the circuitsfor the analog-to-digital conversion 108 are also integrated incomponent 301. The IC 301 defined in this way enables a radicallysimplified system design, which leads to reduced device costs due to thesemiconductor technology used. In addition, integrated circuits 201, 301can also be manufactured in packages, which eliminates the need forcost-intensive semiconductor bonding in the production process.

If significant cost savings can be achieved on the part of thesemiconductor components through the change of technology, simplifiedsystem design and more cost-effective production, the extremerequirements in the field of level measurement bring with them technicalchallenges that must be overcome in order to enable the use of highlyintegrated chips (e.g., RSOC) in industrial level measurement devices.The key to solving the problems described above is the realization that,in contrast to the target markets of automotive and automation, staticor extremely slowly changing reflective objects can regularly be assumedin the area of level measurement.

FIG. 4A comparatively shows a first exemplary operating sequence for alevel radar gauge 101 and FIG. 4B shows a typical operating sequence fora radar gauge 100 according to an embodiment of the invention.

In the operating sequence of FIG. 4A, the frequency 401 radiated byantenna 104 is typically modulated linearly from a start frequency f0 toa stop frequency f1 during a measurement run. Since this operating modehas been optimized for the measurement of static targets withsimultaneous high requirements for the suppression of noise, thisfrequency sweep 402 is performed very slowly. Typical sweep times forthe T 403 are in the range from 1 ms to 5 ms. The radar chips 201, 301are developed by semiconductor manufacturers primarily for theobservation of mobile targets. Consequently, only one operating modewith one or more directly successive individual sweeps 404, 405, 406 canbe controlled via the control interface 203, 303. The duration T0 407 ofsuch a single sweep is orders of magnitude smaller than that of theprevious radar units. Typical values for the time T0 407 range from afew microseconds to several 100 microseconds. Operation of the radarunit with a single sweep of this type therefore leads, depending on thesystem, to an increase in the noise level of typically 20 to 30 dB.There is also the problem that the echo signals of successive sweeps404, 405, 406 cannot be examined for echoes at the speed required forthis.

The new radar units 100 are therefore equipped with a noise reductiondevice or unit 206, 303, the operation of which will be explained inmore detail in FIGS. 5 and 6. It should be noted that the noise levelreduction unit 206, 303 can be part of the evaluation processor 109 andcan be implemented on it by software routines.

However, it may also be intended to implement the noise level reductionunit 206, 303 by means of one or more programmable logic devices (GAL,FPGA) or by a specialized ASIC directly as hardware circuit.

FIG. 5 shows another exemplary operating sequence. The radar measuringinstrument 100 emits a sequence of individual sweeps 404, 405, 406 inthe direction of the product surface 105 and receives the digitized echosignals 207, 304 essentially simultaneously. The resulting digitizedintermediate frequency signals 207, 304 are first stored in a memoryarea in the noise level reduction unit 206, 303. After completion of thehigh-frequency measurement at time 501, the data 601 in the memory arefirst logically grouped in such a way that the data acquired during asingle sweep 404, 405, 406 are combined to form a group A, B, . . . .The averaging unit 206, 303 calculates a resulting averaging vector IF(602) from these subgroups by determining the arithmetic mean value 604for the individual samples 603. It may be provided that the radar module201, 301 is parameterized in such a way that the number of transmittedsweeps N 404, 405, 406 is equal to a power of two. The division by Nrequired for each digit 604, 605, 606 to be determined can then beimplemented in a particularly efficient manner by using a shiftoperation in a digital computing system. The resulting IF signal 602 canbe further processed according to the known procedures, i.e., it can beconverted into an echo curve, in particular by FFT, and examined forechoes and their position. Averaging reduces the noise level in the IFsignal 602, which is essential for processing extremely small reflectionsignals. It may be intended to parameterize the radar chips 201, 301 insuch a way that the duration of a cascade of single sweeps 404, 405, 406essentially corresponds to the time span T 403 of current levelmeasuring instruments.

However, due to the change in semiconductor technology from GaAs toSiGe/CMOS, it cannot be assumed that this measurement time 501 willresult in a similarly low system noise as existing measurement devices101. Another aspect of the invention therefore provides for an extendedor alternative averaging mechanism to achieve a further reduction of thenoise level. Since, in the environment of two-wire technology, theoperation of power-hungry radar components always requires the use of anenergy management unit, the method according to FIG. 7 also does justiceto this aspect.

The modified measuring procedure starts in start state 701 withdeactivated radar chip. In step 702, the radar chip 201, 301 isactivated. This can be done by switching on the supply voltage of thechip and/or if necessary by writing a corresponding parameter sequencevia interface 203, 305. In step 703, the radar chip sends at least onesequence 404, 405, 406 to sweeps, receives it again and processes it toan intermediate frequency signal which is detected by a noise levelreduction unit 206, 303, if necessary by using an A/D converter 108. Instep 704, the radar chip 201, 301 is deactivated again to save energy.In step 705, the detected intermediate frequency values 601, 603 areconverted by the noise level reduction unit 206, 303 into a firstaveraged intermediate frequency signal 602 according to the procedure inFIG. 6. In step 706, a check is made as to whether a predetermined noisesuppression level has already been reached. If this is not the case,step 707 first checks whether there is sufficient energy in the sensorand here in particular in the power supply unit 110 to transmit afurther radar signal detection sequence as shown in FIG. 5. In the eventof a power deficit, step 708 is initially retained until sufficientpower is available. Then the sensor begins to acquire further echosignals with step 702. As soon as sufficient echo curves have beenaveraged, it can be determined in step 706 that a specified noisesuppression level has been reached. In step 709, the sensor proceeds todetermine an echo curve from the resulting averaging curve 602 formed byseveral cycles 702 to 705 according to known procedures. In step 710,the product echo and its position within vessel 113 is also determinedaccording to known methods. The measured value obtained in this way ismade available to the outside in analog and/or digital form in step 711.The measuring procedure ends in condition 712. From the describedsequence it is clear that, in the context of the use of highlyintegrated RSOC's within a level measuring instrument, continuousmonitoring and control of the energy level in the sensor is generallynecessary. The power supply unit 110 can be modified for this purposeand to directly instruct the processor 109 to set the radar chip 201,301 with appropriate parameterization sequences into an energy-savingstate. It can also be provided that the processor 109 takes over thiscontrol itself. It may also be provided that the radar chip 109 has atemperature sensor which is read by the processor. When a pre-settablemaximum temperature is reached, if necessary taking into account thecurrent ambient temperature and, if necessary, taking into accountpre-set limit temperatures due to explosion protection requirements, theprocessor can deactivate the radar chip even if there is a sufficientenergy level to lower the temperature within the 201, 301 block. Thisaspect can also be implemented application-specifically for use of theRSOC's in the level sensor.

FIG. 8 shows a further version of a level measuring instrument 100. Thesensor again has at least one radar chip 301, which is implemented inSiGe or CMOS technology. The maximum emitted power that can be generatedin this technology is in principle lower than with the GaAs componentsused up to now. Due to the higher integration density, however, it ispossible to implement several transmit channels 804, 805 and/or severalreceive channels 806 on one radar chip. It may also be possible toimplement several transmit and/or receive channels 804, 805, 806 byinstalling several radar chips 301, which can still be economical due tothe dramatically reduced system costs compared to the radar systemsknown to date. One aspect of the invention is now to link at least twoof the transmitting channels 804, 805 and/or receiving channels 806 witheach other by means of a signal level increasing device or unit 802. Inthe example in FIG. 8, two transmit channels 804, 805 are currentlybeing combined with the aid of an inverse Wilkinson divider to form aresulting transmit signal 807. The two transmission channels 804, 805must be controlled by setting corresponding control commands 808 in sucha way that both transmission signals are active during a measuring cycle404, 405. The combined signal 807 is forwarded to the antenna withalmost double the power via the transmit-receive switch 803. By thedescribed measure it can be achieved that the transmitted signal reachesa level which is equal or higher than the level of the transmittedsignal of known level sensors 101. The Wilkinson divider shown in FIG. 8can alternatively be replaced by a balun realized in microstrip linetechnology, whereby the control 808 is then carried out in such a waythat the two transmitted signals 804, 805 are generated with a 90° phaseshift. It can also be planned to omit the transmitting and receivingswitch 803 and to realize the level measuring instrument with separatetransmitting and receiving antennas. In addition or alternatively, itcan be intended to detect the reflected signals with several channels ifseveral receiving channels are available, and to realize the signallevel increasing unit on the digital signal processing side in softwareor programmable logic.

FIG. 9 shows an application of the invention in the context of a levelmeasuring instrument 100 which detects the topology of a product. Theradar chip 109 has several transmitting and/or receiving channelsconnected to antennas 902. The control processor 109 has a noise levelreduction unit 303 which during several measuring cycles 404, 405, 406averages the echo signals converted by the receiving channels in RSOC301. In this way, the noise of the signals is reduced. If this hasfallen below a pre-settable value, the noise-reduced signals areforwarded to a beam forming unit 903, which in conjunction withalgorithms for digital beam forming can determine the topology of a bulkmaterial surface 105.

FIG. 10 shows a further development with a highly integrated RSOC 1001,which combines the functional units of the 301 radar chip with thefunctionality of a 1002 calculator. Within the arithmetic unit 1002, anoise level reduction unit 303 is implemented, which compensates for thesemiconductor technology deficits with respect to noise. In order tomeet the requirements of limited conduction, a modified power supplyunit 1003 is provided which provides a larger energy storage thanprevious power supply units 110. Thus, the RSOC unit 1001 can becontinuously activated over several sweeps 405, 406, 407 and, ifnecessary, several measurement cycles 713, and only deactivated after ameasured value has been determined. The memory contents of averagingunit 303 are lost in the deactivated state, but the current measuredvalue can still be signaled externally by power supply unit 1003.

FIG. 11 shows another embodiment of a level meter 100, where a low-powerFPGA 1101 is provided between the processor unit 109 and the radar chip301, which is supplied with an external operating clock during a periodof time when the radar chip 301 is active, and can thus implement thefunctionality of the noise level reduction unit 303. When averaging overseveral measurement cycles 713, the processor 109 can change to anenergy-saving state, and the procedure is implemented by the low-powerFPGA. During any necessary pauses 708, only the clock supply is removedfrom the FPGA, which massively reduces its power consumption, but keepsthe partially averaged measurement values 601, 603 in the memory of theFPGA.

FIG. 12 shows a level measuring instrument 100 detecting the topologyaccording to the diagram in FIG. 9, but it differs from the previouslyshown version by the installation of a large number of radar chips 301,which contributes to an enlargement of the aperture of the effectivelyeffective antenna after completion of the digital beam forming and thusto an improved imaging quality of the measuring instrument.

Thus a level measuring device with at least one low-cost integratedradar chip is provided, which has a device for increasing thesignal-to-noise ratio of these components, a device for reducing theenergy consumption of these components, and/or a device for limiting theheating of the circuits.

An embodiment of the invention can be seen in the fact that the levelmeasuring device for level and/or topology detection comprises at leastone radar module (RSOC), wherein the radar module comprises at least oneintegrated analog-to-digital converter for providing digitizedintermediate frequency signals, and wherein the level measuring devicecomprises at least one noise level reduction device and/or a signallevel increasing device and/or an energy management device.

FIG. 13 shows a flow chart of a process according to an embodiment ofthe invention. In step 1301, each of a plurality of transmissionchannels generates a high-frequency transmission signal which istransmitted in each case. In step 1302, the corresponding receivesignals are received by several receive channels. These steps can beperformed by a radar system-on-chip. In step 1303, the signal-to-noiseratio of one or all received signals is increased by averaging theresults of several measurements carried out in succession. Inparticular, provision may be made for averaging the digitizedintermediate frequency signals of successive measurements. Eachmeasurement shall be performed by ramping the transmitted signal througha frequency ramp. In step 1304, it is determined that the measurementresult is in need of improvement, and in step 1305, two or more of thetransmit channels are combined to increase the power of the resultingcombined transmit channel.

In addition, it should be noted that “comprising” and “having” does notexclude other elements or steps and the indefinite articles “an” or “a”do not exclude a plurality. It should also be noted that features orsteps described with reference to one of the above examples of executionmay also be used in combination with other features or steps of otherexamples of execution described above. Reference numerals in the claimsare not to be considered as restrictions.

1.-13. (canceled)
 14. A level measuring instrument, comprising: amicrowave integrated circuit in a form of a radar system on chip withseveral transmission channels, each configured to generate ahigh-frequency transmission signal, and one or more receiving channels,each configured to receive reflected transmission signals from a productsurface; a noise level reduction device configured to increase asignal-to-noise ratio of a received signal, which relates to thereflected transmitted signals from the product surface, by averagingresults of several measurements carried out in succession in time;and/or a signal level increasing device configured to combine two of theseveral transmission channels to produce a combined transmission signalwith increased power and/or to combine two of the receiving channels toproduce a combined reception signal with increased power.
 15. The levelmeasuring instrument according to claim 14, wherein the noise levelreduction device is further configured to determine, after averaging theresults of the several measurements carried out in succession in time,whether a sufficient number of measurements have been averaged and, ifnecessary, to trigger further measurements, results of which are alsofed to the averaging.
 16. The level measuring instrument according toclaim 14, wherein the level measuring device is configured as afrequency-modulated continuous-wave signal (FMCW) level measuring deviceand each of the measurements carried out in succession in time comprisesa frequency sweep.
 17. The level measuring instrument according to claim14, wherein the microwave integrated circuit comprises at least oneintegrated analog-to-digital converter, configured to convert a receivedsignal into a digitized intermediate frequency signal which is due toone or more reflected transmitted signals from the product surface. 18.The level measuring instrument according to claim 14, wherein an antennais connected to at least two of the transmission channels.
 19. The levelmeasuring instrument according to claim 14, wherein the microwaveintegrated circuit is based on BiCMOS technology.
 20. The levelmeasuring instrument according to claim 14, wherein the microwaveintegrated circuit is based on SiGe technology.
 21. The level measuringinstrument according to claim 14, wherein the microwave integratedcircuit is based on HF-CMOS technology and comprises high frequencycircuit parts configured for frequencies of 75 GHz or more.
 22. Thelevel measuring instrument according to claim 14, further comprising aprocessor and a temperature sensor, which is configured to be read outby the processor, wherein when a predetermined maximum temperature isreached, the processor is configured to deactivate the microwaveintegrated circuit even if a sufficient energy level is present to lowera temperature within the microwave integrated circuit.
 23. The levelmeasuring instrument according to claim 14, the level measuringinstrument being further configured to detect a topology of a medium ina vessel.
 24. A method for measuring a level of a medium in a containeror a topology of a surface of the medium, comprising the steps of:generating a high-frequency transmission signal with one of severaltransmission channels; receiving transmitted signals reflected from aproduct surface with several receiving channels; increasing asignal-to-noise ratio of a received signal, which is due to thetransmitted signals reflected from the product surface, by averagingresults of several measurements carried out in succession; and/orcombining two of the transmission channels to produce a combinedtransmission signal with increased power and/or combining two of thereceiving channels to produce a combined reception signal with increasedpower.
 25. A nontransitory computer-readable storage medium having aprogram stored therein, which, when executed on a processor of a levelmeasuring device, instructs the level measuring device to perform thesteps of the method according to claim 24.